There is known a stapler provided with: a magazine formed with a containing portion for containing connected staples and formed with a striking path for striking and guiding a staple at a front end portion thereof; a forming plate opposed to the striking portion of the magazine for forming a staple member in a straight shape into a staple in a C-shape; a forming and striking mechanism comprising a driver plate for striking the staple formed in the C-shape to sheets to be bound, wherein the connected staples are charged to the containing portion of the magazine, the connected staples are supplied to the striking path by a supply mechanism formed at the magazine, forming the staple member at a front of the connected staples by the forming and striking mechanism to be struck out from the striking path to the sheets to be bound and folding to bend a staple leg penetrated through the sheets to be bound by a clincher mechanism arranged on a lower side of the magazine along the back face of the sheets to be bound to thereby bind the staple.
According to the conventional stapler, the driver plate and the forming plate are simultaneously operated at the same timing, the driver plate is arranged in correspondence with the striking path for striking to guide the staple to the sheets to be bound, and the forming plate is arranged to form a staple member frontward from the driver plate by one piece or two pieces of the staples (on a rear side in a direction of feeding the connected staples). (Refer to, for example, JP-B2-2663800) Therefore, when the staple at inside of the striking path is struck by the driver plate, the staple member which is one piece or two pieces short of the struck staple is formed in the C-shape by the forming plate.
When a new staple is charged or when there is carried out an operation of removing a staple jammed in the striking path from the striking path, staples formed above the striking path and a staple guide are removed. Therefore, it is necessary to operate to idly make the stapler strike until a front portion of the connected staples is supplied to a position of the forming plate and a staple member is formed in the C-shape to be supplied to the striking path. By repeatedly carrying out the idle striking operation by a plurality of times, the formed staple is supplied into the striking path and the staple is made to be able to be struck out.
However, there is a case in which a staple binding apparatus included in an apparatus of a copier or the like includes a plurality of pieces of staplers for simultaneously binding a plurality of portions of sheets to be bound. In such an apparatus, when there is carried out the idle striking operation for supplying the formed staple to the striking path after removing jam of a single piece of the stapler, also other stapler is simultaneously operated and the staple is struck out from the other stapler. Therefore, there poses a problem that not only the staple is wastefully consumed but also the struck staple is dropped at inside of the apparatus to cause a failure or the like.
Further, as other conventional art (refer to, for example, JP-B-64-011428), as shown by FIG. 12A and FIG. 12B, there has already been proposed a stapler constituted by a driver plate provided to be opposed to a striking path 30 for striking out and guiding a staple formed in a C-shape, a forming plate 32 formed on two side faces of a driver plate 31 and operated on a plane the same as that of the driver plate 31, and an anvil 33 formed to be able to advance into the striking path 30 for forming a staple member in a straight shape into a C-shape in cooperation with the forming plate 32. According to the stapler, as shown by FIG. 12A and FIG. 12B, the staple member in the straight shape at a front of connected staples is supplied to a recess portion of the anvil 33 advanced into the string path 30, first, the forming plate 32 is driven to form the staple member in the straight shape arranged at inside of the recess portion of the anvil 33 into a C-shape and thereafter, as shown by FIG. 13A and FIG. 13B, the anvil 33 advanced into the striking path 30 is escaped from the striking path 30 by driving the driver plate 31, and the formed staple is struck out from the striking path by the driver plate 31.
According to the stapler, the staple member in the straight shape at the front of the newly charged connected staples is supplied into the striking path 30 by a supply mechanism, the staple member is formed into the C-shape by the initially driven forming plate 32 by operating the stapler and is struck out from the striking path 30 by the driver plate 31 which is driven thereafter. Therefore, it is not necessary to carry out the idly striking operation for supplying the staple formed by the forming plate 32 to the striking path 30 and even in an apparatus mounted with a plurality of pieces of staplers, in the idling striking operation, the staple is not struck out from other stapler.
However, according to the stapler, when the final staple member in the straight shape of the connected staples is supplied to the striking path 30, as shown by FIG. 14, there is a case in which the staple member is rotated at an upper face of the anvil 33 by operation of being pressed by a front portion of the connected staples which are supplied from a rear side. The staple member is normally formed in a shape of an oval shape or the like in which a width dimension and a thickness dimension differ from each other and therefore, when the staple member is rotated, there is a case of bringing about a failure in forming or a failure in staple binding as a result of striking out the staple having the failure in forming. Although in order to prevent the staple member from being toppled, it is possible to increase dimensional accuracy of a supply path of the staple and a containing portion of the staple of the anvil, there poses a problem that fabrication cost is increased in order to highly maintain the accuracy owing to the fact that a ratio of vertical and horizontal dimensions of a section of the staple member is small.